


Compressibility

by Grub2517



Category: How to Train Your Dragon (Movies)
Genre: Hurt Hiccup Horrendous Haddock III, Light Angst, Near Death Experiences, Post-Traumatic Stress Disorder - PTSD, Whump, hiccup!whump
Language: English
Status: Completed
Published: 2021-03-14
Updated: 2021-03-14
Packaged: 2021-03-22 14:42:09
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,914
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/30040266
Author URL: https://archiveofourown.org/users/Grub2517/pseuds/Grub2517
Summary: Compressibility: an aerodynamic phenomena approaching the speed of sound that was encountered many times in the post WWII period… often with fatal consequences. Young and daring Hiccup is unfortunately unaware of this phenomena, and it costs him dearly.
Kudos: 8





	Compressibility

Hiccup couldn’t describe what it was like to fly, to be _free_ of all of life’s problems, even if only for a short while. He had to admit though flying in itself got rather tame after a while, and he had certainly picked up a competitive streak from Astrid. They were already the fastest, and most nimble, and most powerful, and most… _everything_ but pushing themselves harder, right to the very edge of dragon’s wings and human’s endurance really did make them better, it showed them just how far they could go and got them both used to staring death in the face without blinking. It’s a fact the 16 year old Hiccup takes great pride in. Which brings us to where we are now... flying as high as they can sustain, ready to dive for the ground. This was the latest in a series of high speed test flights meant to see just how fast toothless could really go. Last week had been impressive enough, but they both felt a slight bit of instability in their controls and had to pull back… they could do better. Now with a new streamlined tail and nothing but sky and forest below them they set off to try again.

“Ready bud?”  
“Mmmurrrr…”  
“Cmon Toothless, I know you enjoy this as much as I do.”

With a slight kick and readjustment of the tail the pair nosed over. Hiccup flattened himself against the saddle, his specially designed helmet helping to cut down air resistance as Toothless guided them into a near vertical dive. It was so unnatural to point yourself straight at the ground while accelerating at such velocity, but this is the kind of rush that the two had come to yearn for. They kept getting faster, and faster, and faster... he would have to pull up soon, but like he had so many times before he steeled himself to hold on just a few seconds longer than last time. This time, it was too long. He felt a gentle nudge from Toothless, the signal to adjust the tail for the pull up… but it wouldn’t move. His blood instantly went cold. He had to pull the tail into position, but the tail was acting like it was set in stone and it would not deploy. He kept trying as the hour long seconds passed, what little give he was getting was from the rope stretching. Through the incredible wind noise he could not speak, he could barely turn his head around to see the tail. There was no obvious problem but it simply would not move. Toothless was fighting hard too, but he couldn’t extend his wings. Toothless was in as much terror as Hiccup, frantically writhing trying to get something to word. If either of them could speak they would be praying to Odin in between screaming obscenities. At the last moment the tail responded just a little bit, Hiccup gave it all his effort to kick the tail into position… an effort which only succeeded in ripping the tail off completely and sending them spiraling completely out of control. Now just feet above the treetops he had just enough time to reflect on the short life he had had and all those close to him. 

With a deafening crash the dragon impacted the ground, and Hiccup’s world went black. He wasn’t there to see Toothless bounce back into the air from the sheer force, slice through another stand of trees, and crash into the next ridge so hard that it left a 3 foot deep trench in the dirt.

——————————————————

The next thing Hiccup felt was pain. A lot of pain. Wincing as he opened his eyes he realized he was in his own house.

“Hiccup! Oh gods, you’re awake!” 

That voice, so familiar and so soothing. 

“Astrid…”

“Slow Hiccup, Slow, Slow… you are still in rough shape.” 

“Whe-- Where’s Toothless?”  
The reply was a warm nudge against his hand, no words were needed to express the amount of relief he felt in that moment. For a moment, just a moment, he was at peace. Then the pain came back and knocked him to reality once more. 

“Odin Hiccup, what happened?”  
“Uhh… Toothless his tail… his tail failed at the worst time I tried to… I tried to…”

“Oh my… you were doing one of your speed tests weren’t you?”  
“Yeah… how did you--”  
“How?! Hiccup, you crashed hard in the woods, you could hear the crash from _here_!”

“What???”

“You don’t think I could hear that?”

“With how far out—Aghh!”

“Easy Hiccup, don’t hurt yourself…”

As it had with Astrid before, the awkwardness and Hiccup’s reluctant nature meant the conversation just died. Toothless positioned himself halfway on the bed to cuddle up closer.

“Uhh, Astrid? How long was I out?”

“Seven days.”

“Seven— wait- a _week?!_ Holy…”

“It’s not the Red Death, but not far from it… can I ask… what happened?”

“We were doing a divebomb test… trying to push the speed even higher…

“And you lost control…”

“No. We didn’t.”

“No?”

“Toothless’s tail malfunctioned… something must’ve jammed somewhere because I couldn’t get it open.”

“And Toothless couldn’t pull you out?”

“We were already going too fast, spreading his wings at that speed would be suicide.”

“And diving into the ground at full speed wouldn’t be?”

Astrid’s argumentative tone earned a strong disapproving growl from Toothless.

“Why didn’t you at least-“

“Astrid if you wanna question what I did why don’t you wait until _you_ get in a situation like that! Wait until _you_ are facing near certain death then you can critique!”

Toothless, clearly not liking the stress this was causing his fragile Human, had finally had enough. He beard his teeth right at Astrid, the growl turning truly menacing. The conversation stopped dead again, it was a few minutes before Astrid spoke.

“I- I’m sorry Hiccup…”

“Ast-“

“No, No what’s done is already done. I shouldn’t be questioning you like that.”

The last bit was quiet, barely above a whisper. It had a valad point, Hiccup would never scold Astrid for a heat of the moment mistake, but Astrid’s tone spoke to a deeper guilt. A deeper emotion, finally revealing the fear that Astrid must've felt and continues to feel.

——————————————————

It was months, literal _months_ before Hiccup and Toothless had recovered enough to fly again, and many more years after that before they dared the realms of high speed flight. As traumatic as it was for both Hiccup liked to look at it as not completely fruitless. In the end, they unwillingly accomplished exactly what they had set out to accomplish, push themselves beyond the limit and stare death in the face. After that, Hiccup was a lot more unflinching and coped better with the stress of combat.

In the years following, Hiccup gradually got back into high speed flight testing and repeated experiments gained valuable new insights. He kept them to himself, but with time, testing and a new, reinforced tail he and Toothless were able to reach and surpass the speeds that nearly killed them. With the Outcast war and later Dragons Edge, they would simply move on and the gang would forget this incident. Until 3 years later.

“Hiccup!”

“I see it, I see it!” 

“Two more hunter ships! Dead ahead!”

“Regroup guys! we can’t let em reach the scauldrons!”

“We don’t have any shots left!”

“Well we’ve gotta drive em back somehow!!”

Hiccup’s mind was running fast as a speedstinger… the pod of scauldrons was almost out to sea, but Ryker knew that too and had barricaded the inlet hard. The riders needed a distraction… something to disrupt the hunters long enough for the dragons to get through. The normally trivial task however was made infinitely more complex by the aforementioned fact: All the fast dragons were out of shots, and the short range dragons were held back by supressive fire. It seemed an impossible situation, but then Hiccup’s mind flashed back a few years. Without time to even warn his riders he shot for the sky, climbing right to the pressipuse where Toothless would stall out, then spun back around and dove. Dragon hunters and riders alike looked on with confusion and disbelief as the black form headed straight for the flagship, the only person unphased seeming to be Ryker himself.

“Sir he’s going too fast, we can’t shoot--”

“He’s out of shots. He’s just trying to distract us, remember the objective.”

“Aye sir.”

With most re-focused on the waters surface, the hunters missed what the dragon riders saw, Hiccup swooping down at breathtaking speed even for a Night Fury, slowly coming out of a steep dive. And he was aiming right between the two ships. It looked pointless as he had no shots left… but then, suddenly, a massive blast seemed to emanate from the dragon. A miniature cone of cloud that was followed only an instant later by a deafening blast. For the riders it was enough to blow them back and leave ringing in their ears… but for the hunters it was like getting hit squarely by a titanwing Thunderdrum. The blast ricocheted between the two ships, blowing both into the rocks on either side of the inlet, shredding the sails, tearing crossbow turrets right off their mountings and sending hunters falling to the decks with their ears bleeding. Then, just a split second later, it was over. Hiccup rejoined the riders, and by the time the hunters finally refocused their efforts he was already long out of range.

“What the hell was that?!”

“Orders Sir?!”

“Everyone reverse the ores! Get us out of here!!”

“What happened to the scauldrons?!”

“It doesn’t matter! Whatever new weapon he has we surely can’t survive another hit!”

Not that it mattered. The distraction had worked and the scauldrons were already long gone. From the backs of their dragons, the riders needed only sit back and watch Ryker turn tail. 

“Hiccup, what did you just do?!”

“And how do we get Barf and Belch to do that?! That was awesom— OWCH! Oww oww oww!”

“Cool eh? I call it a sonic boom.”

“Sonic boom?”

“Remember those flight tests a few years back?”

“The one that almost killed you?!”

Astrid’s firm tone put a hitch in Hiccup’s excitement, adding a pang of anxiety but he had already started talking…

“Yeah, _that_ flight. I eventually found out what it was and how to control it. From what I can tell, as we reach our peak speed it gets so fast that the air around us explodes. It creates a sonic wave, like a thunderdrum but more powerful. I never thought I’d actually use it but...”

“Fascinating…”

“Save it Fishlegs, we can talk about it back on the Edge.”

“Well, whatever it was it sure was effective.”

“Needless to say I’m not gonna do that again… unless it’s a very dire emergency. It’s just too destructive.”

“Well that’s so Hiccup… he finds what may be the most effective weapon we have against the hunters and yet he refuses to use it because it’s ‘too powerful’ in his mind.”

This time it was Hiccup’s tone and commanding authority that surprised the riders.

“ _Exactly._ Snotlout. I think sometimes you guys forget we’re not fighting against the hunters, we’re fighting for the dragons. This is not about destruction, and something like that is definitely where I draw the line. In all this fighting, let’s not forget who we really are.”

FIN

**Author's Note:**

> By the way, the use of shockwaves as a weapon is a real tactic in the real world. Even at high altitudes sonic booms can cause problems, but a military jet creating a sonic boom at ground level can literally cause as much damage as a bomb going off. Hope you learned something.


End file.
